High Catalytic Efficiency of Lignin Depolymerization over Low Pd-Zeolite Y Loading at Mild Temperature

Abstract

GRAPHICAL ABSTRACT | High catalytic efficiency of lignin depolymerization over low Pd-zeolite Y loading at mild temperature. This article reported a novel low-temperature process for aromatics production through lignin depolymerization catalyzed by 0.1 wt% Pd-zeolite Y catalyst prepared by a facile method. Under the same reactive condition, the as-prepared Pd-zeolite Y catalysts exhibited much higher catalytic efficiency than zeolite Y or commercial Pd/Al2O3-zeolite composites. The selectivity of the Pd-zeolite Y toward lignin depolymerization was also much higher than the other commercial zeolite-based catalysts. With the presence of hydrogen, aromatics were the predominant products with high yields of phenols and dimers (over 99%). The as-obtained aromatics can be promising feedstock for production of fuels or chemicals for various applications. Results revealed that the Pd-zeolite Y catalyst is a highly active catalyst for the cleavage of lignin interlinkages, especially the C-O-C bonds by hydrogenolysis.

2‐step lignin‐first catalytic fractionation with bifunctional Pd/ß‐zeolite catalyst in a flow‐through reactor

“…Additionally, given the well-established effect of transition metal catalysis on increasing monomer yield during lignin-first fractionation a plausible optimization strategy could involve the combination of metal and zeolite catalysis for this reaction. [8,34,35] Even though the use of transition metal catalyst supported on zeolites has been extensively studied for high temperature biomass conversion strategies such as pyrolysis with good results, [36,37] the use of zeolite-supported metal catalysts under lignin-first conditions is a field that remains largely unexplored. Particularly the case of metal supported ß-zeolite for lignin-first has not been investigated, to the best of our knowledge.…”

“…Such information would be key to envision and further optimize a 2‐step fractionation strategy in which the process conditions for lignin solvolysis and zeolite assisted depolymerization/stabilization of lignin liquors are tuned independently. Additionally, given the well‐established effect of transition metal catalysis on increasing monomer yield during lignin‐first fractionation a plausible optimization strategy could involve the combination of metal and zeolite catalysis for this reaction [8,34,35] . Even though the use of transition metal catalyst supported on zeolites has been extensively studied for high temperature biomass conversion strategies such as pyrolysis with good results, [36,37] the use of zeolite‐supported metal catalysts under lignin‐first conditions is a field that remains largely unexplored.…”